Ibn Umar reported: A man asked the Prophet, peace and blessings be upon him, “Which places are the most evil?” The Prophet said, “I do not know until I ask Gabriel.” So he asked Gabriel and he said, “I do not know until I ask Michael.” So he came and then the Prophet said, “The best places are the mosques; and the most evil places are the markets.”

[Sahih ibn Hibban, Number 1633, Sahih]